chapter 3: periodic properties of elements

periodic property

repeating trends in chemical properties on the periodic table

periodic law

states that physical and chemical properties of elements recur in a systematic and predictable way when elements are arranged in order of increasing atomic mass

main-group element

those found in s- and p-blocks of periodic table

transition element

elements found in groups 3-12 of periodic table

family

group of elements with similar chemical properties

electron configuration

describes arrangement of electrons within atom or molecule

ground state

lowest energy state of an atom, molecule, or ion

orbital diagram

common way of showing electron configuration in which orbitals are shown as boxes and electrons as arrows

pauli exclusion principle

no electrons in the same atom can have the same set of four quantum numbers

degenerate

two or more orbitals have the same energy level

coulomb’s law

describes electrostatic force between two charged particles

shielding

describes how inner electrons reduce attraction between nucleus and outer electrons in an atom with multiple electrons

effective nuclear charge

net positive charge experienced by electron in a multi-electron atom

penetration

proximity to which an electron can approach to the nucleus

aufbau principle

describes how electrons are arranged within an atom’s orbitals

hund’s rule

electrons will individually occupy each orbital within a subshell before pairing up in the same orbital, and all unpaired electrons within a subshell will have the same spin

valence electrons

electrons in the outermost shell of an atom that are involved in chemical bonding

core electrons

electrons that are not valence and do not participate as directly in chemical bonding

noble gases

group of six elements characterized by their extremely low reactivity

metal

class of elements characterized by their high electrical and thermal conductivity, metallic luster, and malleability

nonmetal

elements that generally lack characteristic properties of metals

metalloid

element that exhibits properties intermediate between those of metals and nonmetals

semiconductor

material with electric conductivity between that of conductor and an insulator

alkali metal

group of chemical elements found in group 1

alkaline earth metal

six chemical elements found in group 2

halogen

any of the 6 nonmetallic elements in group 17

van der waals radius

radius of imaginary hard sphere representing distance of closest approach for another atom

covalent radius

half the distance between the nuclei of two identical atoms that are covalently bonded together

atomic radius

distance between nucleus of an atom and its outermost orbital of electrons

paramagnetic

behavior of a substance that is weakly attracted to a magnetic field

diamagnetic

behavior of a substance that is weakly repelled by a magnetic field

ionization energy

minimum energy required to remove an electron from a gaseous atom or ion

electron affinity

change in energy when an electron is added to a neutral gaseous atom to form a negative ion